This invention relates to use of elutable coatings on medical devices for the purpose of delivering compounds.
The systemic administration of drug agents, such as by intravenous means, treats the body as a whole even though the disease to be treated may be localized. Thus, it has become common to treat a variety of medical conditions by introducing an implantable medical device partly or completely into a body cavity within a human or veterinary patient. For example, many treatments of the vascular system entail the introduction of a device such as a stent, catheter, balloon, guide wire, cannula or the like. One of the potential drawbacks to conventional drug delivery techniques with the use of these devices being introduced into and manipulated through the vascular system is that blood vessel walls can be disturbed or injured. Clot formation or thrombosis often results at the injured site, causing stenosis (closure) of the blood vessel.
Other conditions and diseases are also treatable with stents, catheters, cannulae and other devices inserted into the esophagus, trachea, colon, biliary tract, urinary tract and other locations in the body, or with orthopedic devices, implants, or replacements, for example.
Other drawbacks of conventional means of drug delivery using such devices is the difficulty in effectively delivering the bioactive agent over a short term (that is, the initial hours and days after insertion of the device) as well as over a long term (the weeks and months after insertion of the device). Another difficulty with the conventional use of stents for drug delivery purposes is providing precise control over the delivery rate of the desired bioactive agents, drug agents or other bioactive material.